Question 216632
The  distance  formula  is,,d =sqrt{ (y2-y1)^2 + (x2-x1)^2 }
.
subst  for,,,(m+4,n),,,,,(m, n-3)
.
d=sqrt{(4)^2 + (3)^2} = sqrt{ 16+9} = sqrt{25} = 5,,,,,which  is  answer  (b)
.